Combined resuscitator and inhalator



y Dec. 6, 1938. c. N. ERicKsoN 2,138,845

COMBINED RESUSCITATOR AND INHALATOR Filed March 15, 1955 3 Sheets-Sheet 1 INVENTOR.

larmes/Mclean ATTORNEY.

Dec. 6, 1938. V c. N. ER|cKsoN 2,138,845

COMBINED RESUSCITATOR AND INHALATOR Filed March l5; 1935' 5 Sheets-Sheet 2 f if 7 i I 1w @l0 Cirence/Wgrz'ckson,

;:D ATTORNEY,

Dec. 6, 1938. c. N. ERICKSON COMBINED RESUSCITATOR AND INHALATOR Filed March l5, 1955 INVBNTOR. ckson.

ATTORNEY.

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Patented Dec. 6, 1.938

PATENT oFFlcE y 2,188,845 COMBINED nEsUscl'rA'ron AND INHALAT Clarence N. Erickson, Glendale, Calif. Application March 15, 1935, Serial No. 11,301

12 Claims.

This invention relates to and has for a main object the provision of a combined resuscitator and inhalator arranged in a single compact unit and adapted for connection with a tank of oxygenA and operative for use as a resuscitator for emergency treatment of persons who have been asphyxiated, drowned, sufocated or seriously shocked by electricity, or for use as an inhalator for supplying oxygen to the lungs in variable i0 quantities depending upon requirements in difierent cases.

Reference is had to Letters Patent of the United States No. 1,893,670, granted to Monroe H. Goodner on January 10, 1933, for Resuscitators,

`1li with respect to which the present invention embodies several distinct improvements, particularly in the provision of an inhalator in connection with the resuscitator, and otherwise as may appear hereinafter.

A further object is to provide an improved type of reducing valve between the oxygen tank and the resuscitator whereby the high pressure existing in the oxygen tank is reduced at the point of supply to a practicable minimum and which is automatically operative and is yet capable of adjustment to meet varying requirements of use.

Another object is to provide an improved form of control means by means of which the instrument may be quickly adjusted as an inhalator or as a resuscitator, and the inhalation and exhalation of a patient controlled accordingly.

This invention contemplates the provision, also, oi improved means, including a sensitive and accurately operating diaphragm anda series of interconnected pistons operating in separate cylinders for so regulating and controlling the pressure and vacuum that the instrument is automatically adjustable to the varying lung capacity of different individuals.

Other objects willv appear as the description of my apparatus progresses.

I havev shown in the accompanying drawings a preferred form of apparatus embodying my invention, in which:

Fig. 1 is a sectional elevation of the apparatus, partly broken away, and disassociated from an oxygen tank, with the elenints shown during a descending stroke of the pistons as in an inhala- 50 tion cycle of operation;

Fig'. 2 is a fragmentary sectional elevation of the same on line 2- 2 of Fig. 1;

Fig.. 3-is a sectional plan on line 3 3 of Fig. 1 showing a mask mounting and flexible connec- 55 tions between the apparatus and the mask;

Fig. 4 is a transverse section of the oxygen inlet, on line 4 4 of Fig. 1;

Fig. 5 is an elevation of the apparatus, partly in section in the plane of Fig. 1 and with the elements thereof positioned as during a descending 5 inhalation cycle of operation;

Fig. 6 is a sectional plan on line 6 6 of Fig. 1;

Figs. '7 and 8 are, respectively, sectional plans on lines 1 1 and 8 8 of Fig. 2;

Fig. 9 is a section of the control valve on line 10 9 9 of Fig. 2;

Fig. 10 is a section, in elevation, of the control valve, online Ill-Ill of Fig. 2;

Fig. 11 is a fragmentary section, in elevation, of means for controlling the vacuum and oxygen 16 pressure in the cylinders, corresponding to but on a substantially enlarged scale with respect to the disclosure in Fig. 2;

Fig. 12 is a sectional elevation of the apparatus in the plane of Fig. 1 showing the elements posi- 20 tioned at the completion of an inhalation cycle of operation;

Fig. 13 is a sectional elevation of a mask operatively connected with a suitable headpiece, in the plane of line I3 I3 of Fig. 3, and arranged for 26 flexible connection with the main apparatus;

Fig. 14 is a perspective view of the apparatus arranged in a compact carrying case and operatively connected with a pair ori oxygen tanks in readiness for use.

In its simplest form the apparatus is arranged in a compact erect unit and includes an elongated vertical cylinder C having a detachable head H at its top which may be formed, as shown, of separable members I, 2 and 3 suitably secured to- 35.

gether in axial alinement and rigidly attached to the cylinder C, or to a top closure 4 nxed in the upper end of said cylinder, as shown in Fig. 1.

Cylinder Chas a pair of'telescoping cylinders 6 and 1 of different size longitudinally disposed 40 therein forslidably receiving pistons 9 and Ill, respectively, togetherwith a relatively larger piston II in the bottom of cylinder C. Cylinder 1 serves as a stem for piston II and is slidable through a partition I2 internally secured to cylinder C andpacked around the cylinder 1, as by means of a gland I3, for preventing communication between the chamber I4 of cylinder C and chamber I5 of cylinder 6. vThe upper end of cyl- 50 inder 1 is i'lxed toand carries piston 9 while piston III is stationarily held on member 5 by means of a depending tube I6 and is positioned in chamber I1 of cylinder .1'. All of said pistons Operate, as hereinafter explained in detail, for 55 regulating and effecting the inhalation and exhalation cycles of operation of the apparatus.

The application of vacuum to the chamber I4, is controlled by means of a sensitive diaphragm D mounted in a chamber I8 formed within member 3 of head H and associated with a control valve V supported on said head. A reducing valve R is provided in head H within a chamber I9 for receiving a supply of oxygen from either one of a pair of tanks T, T adapted to be held in a suitable carrying case 20 (see Fig. 14) and connected with chamber I9 through the reducing valve R in such a manner that the high pressure in said tanks will be reduced to a practical operating pressure for a resuscitating and inhalation apparatus.

To this end head H has a pair of oppositely extended arms 2|, 2|, each with a yoke 22 and a screw clamp 23 thereon by means of which the necks of the tanks T are held on the arms in such a manner that oxygen from the tanks will flow through intake valves 24, 24 into a diametrical passage 25 formed in a portion 26 of the head and thence outwardly through a vertical passage 21 in a jet outlet 28. Reducing valve R 1S mounted on the bottom of head member I and includes a valve closure 29 which is urged upwardly into engagement with the end of jet 28 by means of springs 30 and is thus tensioned so as to resist the discharge of oxygen from the jet into chamber`l9, thereby limiting the pressure in said chamber to a predetermined extent.

Member I also supports a diaphragm 3| at its periphery and the central portion of the diaphragm is attached to a yoke 32 rigid with valve member 29, Head member 2 encloses a tensioning spring 33 which compresses between yoke 32 and a collar 34, and a manually adjustable screw 35 is adjustable on the hub of member 2 and engages collar 34 for varying the pressure on valve member 29. Thus, the valve R will resist the high pressure of the oxygen in passage 25 and limit the volume and pressure supplied to the chamber I9, in accordance with the adjustment of screw 35.

The oxygen from a tank T issues through jet 28 intochamber I9 and builds up a pressure against diaphragm 3|, thereby compressing spring 33 which is under the control of screw 35. The adjustment of said screw in opposite directions correspondingly varies the tension of spring 33 and the pressure against diaphragm 3|. Springs 30 which bear upon theyalve member 29 tend to close the valve seat of jet 28 and operate against the tension of spring 33 so that when screw 35 is turned suiliciently in a given direction the tension of spring 33 is relieved. When screw 35 is turned to a maximum extent in an opposite direction the ow of oxygen is completely shut off. Obviously, any desired intermediate pressure may be obtained by proper manipulation. of screw 35.

The control valve V is interposed between the diaphragm chamber I8 and a mask M (Fig. 13) and by means of flexible tube connections 36 and 31 the apparatus may be adapted and readily adjusted for operation as an inhalator or a resuscitator when the mask M is applied to the patient. Valve V is rotatably mounted on an extension 39 integral with head member 3, is tapered to fit a bore 40 and is operable by means of a handle 4I and has peripheral recesses 42 and 43 which terminate at the top and bottom of said valve and have their opposite extremities open at diametrically opposite points on the periphery, 8S

shown in Fig. 2, for registration, respectively, with passages 44 and 45 in extension 39 with which the flexible tubes 36 and 31 communicate.

Tubes 36 and 31 connect at their other ends with passages 46 and 41 extended from the mask mounting 38 and leading to chambers 48 and 49, respectively, in said mounting. Said chambers 48 and 49 have spring urged inhalation and exhalation valves 50 and 5| forming closures for ports 52 and 53, respectively, for regulating communication between the chambers 48 and 49 and a common chamber 54 in the mask mounting 38 and thence with the interior of the mask M. Said valves are suitably caged and each has a spring 55' urging it into closed position. Auxiliary chambers 56 and 51 are also provided in member 38 above the chambers 48 and 49, respectively, chamber 56 having a spring urged safety valve 58 therein, and chamber 51 having a manually operable auxiliary exhalation valve therein, each of the chambers 56 and 51 having one or more outlets 56 to the atmosphere. Mask M has an air cushioned rubber applicator M adapted to t over the face of a patient, as in other forms of apparatus for similar purposes.

It will be understood that it is the purpose of this invention to arrange the control means, in-

-cluding the diaphragm D and control valve V and associated mechanism, so that oxygen at a suitable pressure may be supplied to the lungs of a patient, regardless of his lung capacity, in regulated volume and in rhythmical impulses, and that the waste products of respiration may be exhaled by vacuum, both the pressure and vacuum being comprehensively controlled and regulated to meet individual requirements. Therefore, chamber I8 in which the diaphragm D is located is always connected with a patients lungs by means of a passage 60, valve V, tube 31, member 38 and mask M, and the pressure in chamber I8 always corresponds to that in the lungs of a patient.

When the pressure in chamber I8 is raised above a predetermined point, diaphragm D is depressed, as shown in Fig. 1, and is held in a depressed position by means of a toggle device including a bifurcated lever 6I pivotally held at 62 and toggle arms 63 and 64 adapted to engage notches in a stud 65 at their inner ends. Said stud is xed at its lower end to diaphragm D so that the movement of the diaphragm will operate the toggles. Toggle 63 is coaxially held at 62 with lever 6I while toggle 64 is composed of a pair of slidably adjustable spring tensioned members pivotally held on lever' 6| at 61. As shown in. Fig. 1 and elsewhere, the diaphragm D is clamped at its periphery to an internal portion of head H by suitable means.

Lever 6I supports at its free end a pair of valves 68 and 69 which, respectively, regulate the application of pressure to chamber I5 of cylinder 6 and the vacuum connection between chamber I4 of cylinder C and diaphragm I8. As shown in Fig, l1, valve 68 is composite and has an upper disc valve member 10 forming a closure for a passage 1| in head member 5 and a lower conical valve member 12 forming a closure for a passage 13 in member 5. A stem 14 carries the valve members 10 and 12 at its lower end and is fixedly attached to lever 6I at its upper end and is 'slidable at an intermediate point in a bore of member 5. Valve 68 is located in a chamber 15 which communicates by means of one or more passages I6 with a lower chamber 11 to which a tube 18 is connected and from which said tube lso leads downwardly in cylinder C to and communicates with chamber I5 at a point 19.

Valve 69 is resiliently mounted on lever 6I above and for closing a vertical passage inl is to create a vacuum in chamber I4 during an expiratory cycle. When the apparatus is used as a resuscitator and as an inhalator the gas is conveyed to and is discharged from the inspiratory cylinder I5 to the mask M.

Normally, pistons 9 and II do not move upwardly to the full limit of a stroke, piston II usually stopping short of an outlet 84 at the top of chamber I4 in cylinder C, but in the event of an overstroke of said pistons, means is provided on member 5 for elevating the diaphragm D slightly so as to initiate the upward movement thereof, as shown in Fig. 1. Said means includes a vertically slidable tube 85 having a anged upper end 86 adapted to engage a pin 81 which is slidable in member 5 and adapted to engage the anged bottom of stud 65 at the center of diaphragm D. Said diaphragm D is movable to a substantial extent in opposite directions to points beyond dead center positions of the toggles 63 and 64 and a triggerl 88 is provided -which is pivoted at 89 on member 5 and has a depending portion 90 seated in an aperture 9| in member 5 and engaged by a spring urged plunger 92 which tends to hold the trigger resiliently in engagement with the diaphragm D, thereby limiting the downward movement of the diaphragm to a predetermined extent, so that when vacuum is created in chamber I4 the diaphragm may be readily elevated from the depressed position shown in Fig. 1. The tension of the plunger is regulated by means of a screw 93 between which and plunger 92\a spring 93" is compressed.

Tube 85 has a resiliently yieldable tongue 94 cut from or attached to the wall thereof and adapted to engage a peripheral hump 95 on stem I6 of piston I0, for locking the tube in its lowered position shown in Fig. 1, or in an elevated position as shown in Fig. 5, when the flange 86 of said tube is engaged by a plate 91 on piston 9. Tube 85 is restored to normally lowered position by means of the engagement of plate 91 with a flange 98 on the bottom of the tube. Tube 85 thus serves to hold diaphragm D upwardly until piston II reaches the bottom of chamber I4.

The function of piston II is to create a vacuum in chamber I4 for rendering the apparatus useful as a resuscitator when the mask Mis appliedV to a lifeless patient. Piston 9 is operative in chamber I5 for the purpose of operating piston II when pressure is applied thereto, and piston I0 operates to preserve a constant pressure in chamber I1 which tends to restore piston II to normally depressed position in chamber I4, in

the same manner as a sprin; would function when interposed between pistons I0 and II.

The control mechanism is arranged to perform a dual function, namely, the regulation and control of the ow of oxygen from a tank T to the lungs of a patient and the outilow of the products of respiration therefrom during a resuscitation operation, and the control of the ow of oxygen to a patient during an inhalation operation. A breathing bag 99 is detachably held on a nipple |00 of valve housing 39 and is in communication with a chamber IOI which has an air inlet' |02 controlled by a valve |03, as shown in Fig. 2. In an inhalation operation the oxygen is directed to the bag 99 and then from the bag to the lungs of a patient, and the inflow and outflcw of the oxygen causes the bag to contract and expand and thus provide means for visibly indicating the operation and the eilect of the operation.

In cases where an excess of oxygen is required for a patient the valve |03 will remain closed but when breathing is induced to a point approaching normality the eiort of the patient will induce a iiow of airfrom the atmosphere through inlet |02 and valve |03.

gas is conducted from passage 1I through valve V to chamber I0| and thence to the breathing bag 99. Gas is exhausted from bag 99 through chamber |0I, valve recess 42 and tube 36 to the mask mounting 38, as hereinbefore explained.

Valve V has an upper chamber |06 Within the hub of handle 4| which is open to the atmosphere at a plurality of points, as by means of orifices |01, |01, etc. and the valve recess 43 is in constant` communication with chamber |0Ii so that the products of respiration may be exhausted to the atmosphere through tube 31 leading from the mask M, passage 43 and chamber |06 during an inhalation operation, provided the auxiliary exhalation valve 58 on the mask is closed; otherwise when said valve 58 is open exhalatio-n will be direct through chamber 51.

When the apparatus is used as an inhalator or as a resuscitator, gas is supplied to chamber I1 of piston stem 1 constantly for applying pressure to piston I I, thereby tending to depress said piston in its cylinder C. Accordingly, gas is fed through a vertical passage |08 which is open to the supply chamber I9 in head H at its upper end and is connected at its lowerv end with a passage |09 in tube I6 by means of a horizontal passage |I0.

Obviously, as piston is raised in its cylinder the air in that portion of cylinder C above said piston is expelled through the venty 84, and

`simultaneously air is expelled from the upper portion of chamber I5 throughone or more vents III in cylinder 6 into chamber Il! o! cylinder C from which the air is vented to the atmosphere through one or more vents I I3. It will be understood that the chamber I I4 below diaphragm D is vented to cylinder 6 by' orifice 3|, so that said diaphragm is free to raise when vacuum is 'aping such energy into useful work in the form vof a respiration by expanding and contracting the lungs of a patient rhythmically and regularly for alternately supplying oxygen to and for exhausting the products of respiration from the lungs until natural respiration is gradually induced. As an inhalator, the apparatus is adapted to supply oxygen in sufcient volume to the lungs of la living patient who has been subjected to partial asphyxiation, shock or otherwise and the apparatus merely assists the patient in performing the respiratory functions. The term inhalator herein used is a coined word employed to qualify the apparatus iny respect to its functioning to supply oxygen to a patient as though said patient had actually inhaled such` oxygen.

When used as a resuscitator, oxygen from tank T will flow from chamber I9, through passages |08 and ||0 into passage |09 of tube I6 and thence to chamber |1 of cylinder 1, thereby creating pressure against piston which tends to hold said piston at the bottom of its stroke in cylinder C., and simultaneously oxygen will flow from passage |08 into and from passage ||0 into passage 13 and thence by valve 12 into chamber 15 and outwardly therefrom through passages 16 through, chamber 11 into tube 18, and thence through inlet 19 to chamber l5 of cylinder 6. Thus, oxygen under pressure is 'applied to the lower side of piston 9 in cylinder 6 for raising said piston and piston I I to which it is connected. 'I'he area of piston 9 is substantially greater than the area of piston exposed to the pressure of the oxygen; hence the pistons 9 and I I will be simultaneously raised in their cylinders against the downward pressure applied to piston in chamber I1.

As pistons 9 and are gradually raised,- the air from their cylinders is expelled to the atmosphere, as hereinbefore described, and suction is created in chamber |4 of cylinder C which is communicated to diaphragm chamber I8 by means of tube 8|, thereby raising the diaphragm D and closing valves 69 and 10, while valve 12 is opened.

The upward movement of piston 9 is normally to a point short of actual engagement by flange 86 of tube 94 with plate 91 of piston 9, and in the event said piston is moved beyond its normal limit the engagement of piston 9 with flange 86 will operate safety pin 81 and effect an upward thrust of diaphragm D if in the meantime the vacuum in chamber I8 is not sumcient to accomplish the operation of the diaphragm. The extent to which the pistons 9 and I I move upwardly corresponds to the capacity of the lungs of a patient.

As hereinafter described, the extent of vacuum in chamber I8 is determined by the character of the connection vbetween the mask M and the patient. It said connection is loose the vacuum in chamber |8 will be insumcient to operate the diaphragm, hence upon an overstroke of the pistons 9 and the safety pin 81 will insure the operation of the diaphragm to the position shown in Fig. 5. As pistons 9 and I I ascend in their cylinders a vacuum is applied to the lungs of a patient from chamber I4 by means of tube 8|, chamber I8, passage 60, tube 31, valve 5| and mask M (see Fig. 3) thus the air and products of respiration are exhausted from the lungs of a patient.

Under all conditions the pistons 9 and will proceed to their extreme bottom positions, upon the completion of an exhalation cycle of'operation and during such movement of the pistons a leather valve ||5 will expand and open as soon as peripheral orifices 6 in cylinder 1 reach a position below piston I0, as shown in Fig. 12, whereupon oxygen will be admitted into chamber I5 through said orifices, and thence to the patient through tube 18, chamber 11, passages 16, chamber 15, by valve 10 which has been opened in the meantime due to return of the diaphragm to lowered position as shown in Fig. 5, through passage 1|, thence through a vertical recess ||1 (see Fig. 10) to and through valve passage 44, tube 36, inlet valve 50 of the mask mounting and mask M to the patient.

The admission of oxygen to the lungs of the patient will continue until suilicient pressure has been built up in chamber |8 above diaphragm D to again reverse the diaphragm and valves 10 and 12. The alternate inhalation and exhalation cycles of operation will continue as long as the valve is adjusted as described and the mask is applied to the patient. During the downward stroke of the pistons 9 and il the Waste products of respiration under piston in chamber I4 are forced by a yieldable cup leather valve ||8 on piston into the upper portion of chamber |4 from which it is discharged to the atmosphere through vent 84.

Preferably, the controlling mechanism is adjusted at the factory so that inhalation ceases when a pressure of four ounces above atmosphere is attained and exhalation ceases when a pressure or vacuum oi' three ounces below atmosphere is attained, thereby insuring against injury to the lungs, distress or discomfort of a patient.

When the apparatus is used as an inhalator, valve V is adjusted so that horizontal recess |04 will aiord communication between passages 12 and |05 and the upper extremities of valve passages 42 and 43 will register, respectively, with tubes 36 and 31, for communication with mask inlet and outlet valves 50 and 5|, respectively. As an inhalator, the pistons 9 and II remain at the bottoms of their strokes, as shown in Fig. 12, and the orifices 6 in cylinder 1 are disposed below the piston I0. Thus pressure of oxygen from chamber |1 will open leather valve ||5 so that oxygen will` flow into and from chamber I5 throughtube 18, chamber 11, passages 16, chamber 15 by the open valve 10 to passage 1| and thence to valve recess |04 and passage |05 into chamber |I, thence to and from the breathing bag 99 to and from valve passage 42 to the patient as described. The patient will exhale through the mask M and valve through chamber 51 of the mask mounting to the atmosphere. If the amount of oxygen supplied to a patient is less than that required, air from the atmosphere will be automatically supplied through auxiliary inhalation valve |03. Valve 58 which is arranged adjacent to the mask exhalation valve 5| is provided` for the purpose of reducing the back pressure on the lungs of a patient when the machine is being used as an inhalator, and is manually adjustable in its seat. Obviously, when said valve is opened to a maximum extent, only atmospheric pressure will have to be overcome in an exhalato depressed positions in their cylinders, and manually operable means for regulating the supply of gas under pressure to said inspiratory cylinder and to said mask, including permanent connections between said cylinders and said mask, and valve means operable whereby the apparatus may be selectively used as a resuscitator while said pistons operate to provide articial inspiration and expiration, respectively,` and as an inhalator while said pistons are stationary for supplying gas to a living patient.

2. An apparatus of the character described comprising: a head provided with pressure and vacuum chambers closed against communication with eachother, means for connecting said pressure chamber with a source of gas supply under high pressure, a reducing valve in said pressure chamber adjustable for limiting the pressure therein, a vacuum operated diaphragm in said vacuum chamber, an inspiratory cylinder, an expiratory cylinder, pistons in said cylinders connected for uniform operation, means for supplying gas from said pressure chamber to and for operating said pistons in opposite directions, a mask applicable to a patient, a spring urged trigger disposed to resiliently'limit the movement of the diaphragm, and a control valve connected with said inspiratory and expiratory cylinders and with said mask whereby on the opposite strokes of said pistons gas may be supplied to and exhausted from the lungs of a patient through said mask, in a resuscitating operation.

3. An apparatus of the character described comprising: a head provided with pressure and vacuum chambers` closed against communication with each other, means for connecting said pressure chamber with a source of gas supply under high pressure, a reducing valve in said pressure chamber adjustable forl limiting the pressure therein, a vacuum operated diaghragm in said vacuum chamber, an inspiratory cylinder, an expiratory cylinder, pistons in said cylinders connected for uniform operation, means for supplying gas from s-aid pressure chamber to and for operating said pistons in opposite directions, a mask applicable to a patient, a control valve connected with said inspiratory and expilatory cylinders and with said mask whereby on the opposite strokes of said pistons gas may be supplied to and exhausted from the lungs oi a patient through said mask, in a. resuscitating operation, and means controlled by said diaphragm for directing the flow of gas to said pistons whereby the pistons may operate successively in opposite directions.

4. An apparatus of the character described comprising: a head provided with pressure and vacuum chambers closed against communication with each other, means for connecting said-pressure chamber with a source of gas supply under high pressure, a reducing valve in said pressure chamber adjustable for limiting the pressure therein, a vacuum operated diaphragm in said vacuum chamber, an inspiratory cylinder, an expiratory cylinder, pistons in said cylinders connected for uniform operation, means for supplying gas from said pressure chamber to and for operating asid pistons in opposite directions, a mask applicable to a patient, a control valve connected with said inspiratory and expiratory cylinders and with said mask whereby on the opposite strokes of said pistons gas maybe supplied to and exhausted from the lungs of a patient through said mask, in a resuscitating operation, and means operative when said inspiratory piston is in a depressed position and said control valve is operated in a given direction whereby said pistons Will remain stationary and gas will ow from said inspiratory cylinder to said mask in an inhalation operation,

5. An apparatus of the character described comprising: a head provided with pressure and vacuum chambers closed against communication with each other, means for connecting said pressure chamber with a source of gas supply under high pressure, a reducing valve in said pressure chamber adjustable for limiting the pressure therein, a vacuum operated diaphragm in said vacuum chamber, an inspiratory cylinder, an expiratory cylinder, pistons in said cylinders connected for uniform operation, means for supplying gas from said pressure chamber to and for operating said pistons in opposite directions, a mask applicable to a patient, a control valve connected with said inspiratory and expiratory cylinders and with said mask whereby on 'the opposite strokes of said pistons gasmay be supplied to and exhausted from the lungs of a patient through said mask, in a resuscitating operation, connections between said expiratory cylinder and said vacuum 'chamber for creating vacuum in said chamber on the upstroke of said expiratory piston, and means operable by said inspiratory piston as the same is moved beyond a normal extent on its upward stroke, for actuating said diaphragm so as to reverse the mechanism to elect an ensuing inhalation cycle, in the event of a loose connection between said mask and a patient.

6. An apparatus of the character described comprising: a head provided with pressure and vacuum chambers closed against communication with each other, means for connecting said pressure chamber with a source of gas supply under high pressure, a reducing valve in said pressure `chamber adjustable for limiting the pressure therein, a vacuum operated diaphragm in said vacuum chamber, an inspiratory cylinder, an expiratory cylinder, pistons in said cylinders connected for uniform operation, means for supplying gas from said pressure chamber to and for operating said pistons in opposite directions, a mask applicable to a patient, a control Valve connected with said inspiratory and expiratory cylinders and with said mask whereby on the opposite strokes of said pistons gas may be supplied to and exhausted from the lungs of a patient through said mask, in a resuscitating operation, and an expansible and contractible breathing bag connected with said control valve for receiving and discharging the gas delivered to a patient and for indicating therespiration of the patient.

7. An apparatus of the character described comprising: a head provided with pressure and vacuum chambers closed against communication with each other, means for connecting said pressure chamber with a source of gas supply under high pressure, a reducing valve in said pressure chamber adjustable for limiting the pressure therein, a vacuum operated diaphragm in said vacuum chamber, an inspiratory cylinder, an expiratory cylinder, pistons in said cylinders connected for uniform operation, means for supplying gas from said pressure chamber to and for operating said pistons in opposite directions, a mask applicable to a patient, a control valve connected with said inspiratory and expiratory cylinders and with said mask whereby on the opposite strokes of said pistons gas may be supplied to and exhausted from the lungs of a patient through said mask, in a resuscitating operation, an expansible and contractible breathing bag connected with said control valve for receiving and discharging the gas delivered to a patient and for indicating the respiration of the patient, said control valve having a valve associated therewith for admitting air from the atmosphere to the gas discharged from said bag when the gas supply exceeds a necessary volume.

8. An apparatus of the character described comprising: a head provided with pressure and vacuum chambers closed against communication with each other, means for connecting said pressure chamber with a source of gassupply under high pressure, a reducing valve in said pressure chamber adjustable for limiting the pressure therein, a vacuum operated diaphragm in said vacuum chamber, an inspiratory cylinder, an expiratory cylinder, pistons in said cylinders connected for uniform operation, means for supplying gas from said pressure chamber to and for operating said pistons in opposite directions, a mask applicable to a patient, a spring urged trigger resiliently resisting movement of the diaphragm, a control valve connected with said inspiratory and expiratory cylinders and with said mask whereby on the opposite strokes of said pistons gas may be supplied to and exhausted from the lungs of a patient through said mask, in a resuscitating operation, said mask having inhalation and exhalation valves for regulating the supply of gas to and the discharge of the proucts of respiration from a patient.

9. An apparatus of the character described comprising: a head provided with pressure and vacuum `chambers closed against communication with each other, means for connecting said pressure chamber with a source of gas supply under high pressure, a reducing valve in said pressure chamber adjustable for limiting the pressure therein, a vacuum operated diaphragm in said vacuum chamber, an inspiratory cylinder, an expiratory cylinder, pistons in said cylinders connected for uniform operation, means for supplying gas from said pressure chamber to and for operating said pistons in opposite directions, a mask applicable to a patient, a control valve connected with said inspiratory and expiratory cylinders and with said mask whereby on the opposite strokes of said pistons gas may be supplied to and exhausted from the lungs of a patient through said mask, in a resuscitating operation,

said mask having inhalation and exhalationv sure chamber with a source of gas supply under high pressure, a reducing valve in said pressure chamber adjustable for Hunting the pressure therein, a vacuum operated diaphragm in said vacuum chamber, an inspiratory cylinder, an expiratory cylinder, pistons in said cylinders connected for uniform operation, means for supplying gas from said pressure chamber to and for operating said pistons in opposite directions, a mask applicable to a patient, a control valve connected with said inspiratory and expiratory cylinders and with said mask whereby on the opposite strokes cf said pistons gas may be supplied to and exhausted from the lungs of a patient through said mask, in a resuscitating operation, said mask having inhalation' and exhalation valves for regulating the supply of gas to and the discharge. of the products of respiration from a patient, and an auxiliary valve associated with the exhalation valve of said mask and manually adjustable for relieving the back pressure on the lungs of a patient during an exhalation cycle of operation.

11. An apparatus of the character described comprising: a head provided with pressure and vacuum chambers closed against communication with each other, means for connecting said pressure chamber with a source of gas supply under high pressure, a reducing valve in said pressure chamber adjustable for limiting the pressure therein, a vacuum operated diaphragm in said vacuum chamber, an inspiratory cylinder, an expiratory cylinder, pistons in said cylinders connected for uniform operation, means for supplying gas from said pressure chamber to and for operating said pistons in opposite directions, a mask applicable to a patient, a control valve connected with said inspiratory and expiratory cylinders and with said mask whereby on the opposite strokes of said pistons gas may be supplied to and exhausted from the lungs of a patient through said mask, in a resuscitating operation, a

stationary piston telescoping into said inspira- `ing said diaphragm in the event of an overstroke of said inspiratory piston and occasioned by a loose connection between the mask and a patient.

12. A combined resuscitator and inhalator comprising pressure and vacuum chambers, means for connecting said pressure chamber with a source of gas supply under pressure, a pressure controlling valve in said pressure chamber adjustable for varying the pressure therein, a diaphragm in said vacuum chamber, an inspiratory cylinder and expiratory cylinder, pistons in said cylinders, means for supplying gas from said pressure chamber to and for operating said pistons in opposite directions, a mask applicable to the patient, a control valve connected with said cylinder and said mask whereby on opposite strokes of said pistons 'gas may be supplied to and exhausted from the lungs of.a patient through said mask in a resuscitating operation, and means operative when said inspiratory piston is in one position and said control valve is manipulated in a given manner whereby said pistons will remain stationary and gas will flow fr'm said inspiratory cylinder to said mask in an inhalation operation.

- CLARENCE N. ERICKSON. 

